Hydraulic exercising machines

Abstract

An exercising machine incorporates one or a pair of hydraulic rams to be actuated by a user. The resistance to effort within the hydraulic circuit can be increased by operating a pump so that hydraulic fluid enters a pressure accumulator to compress gas therein. A pressure gauge indicates the pressure level set and the circuits for the two rams can be set individually, selectively bleeding off hydraulic fluid to a reservoir by operation of valves. Consequently the exercising machine can be set to a number of required operating levels without resorting to the use of weights as with conventional exercising machines.

We claim: 
     
       1. An exercising machine, comprising (a) a frame;   (b) an exercise member connected with said frame for movement relative thereto;   (c) a hydraulic piston and cylinder unit connected between said frame and said member for providing a biasing force resisting movement of said member relative to said frame; and   (d) hydraulic control means for controlling the biasing force of said piston and cylinder unit, said hydraulic control means including (1) a pump for pumping hydraulic fluid to said piston and cylinder unit;   (2) a hydraulic line connecting said pump with said piston and cylinder unit, whereby said pump is operable to establish a predetermined starting pressure within said piston and cylinder unit;   (3) a pressure gauge connected with said hydraulic line for registering the hydraulic pressure therein; and   (4) pressure accumulator means incorporating a compressed gas and connected with said hydraulic line for pressurization by said hydraulic fluid, said accumulator means comprising (i) first and second accumulator units hydraulically connected in series, each of said units being connected with said hydraulic line;   (ii) an on/off valve arranged in the series connection between said units separate from said hydraulic line; and   (iii) a two-way valve link arranged in said hydraulic line between said pump and the line connections of said first and second accumulator units, said two-way valve link being selectively movable between a first position connecting said pump solely with said line connection to said first accumulator unit, and a second position connecting said pump solely with said line connection to said second accumulator unit, whereby the volume of said accumulator means communicating with said hydraulic lines may be selected in accordance with the selected positions of said on/off valve and said two-way valve link.       
     
     
       2. An exercising machine according to claim 1 wherein said two accumulator units have different volumes. 
     
     
       3. An exercising machine according to claim 1, including two movable members which can be moved with respect to the frame independently of one another and which act against the bias of separate hydraulic piston and cylinder units having similar respective associated hydraulic control means. 
     
     
       4. An exercising machine according to claim 3, wherein a common pump supplies the two circuits. 
     
     
       5. An exercising machine according to claim 4, wherein valves are incorporated in the two circuits to enable the pressure levels in each circuit to be set independently of the other. 
     
     
       6. An exercising machine according to claim 1, wherein the frame incorporates support structure for supporting parts of the body of the user of the machine.